Asterís NKP Berkshire #779

an assembly review by Howard Freed

with photos by Jason Musheno

I first set eyes on Asterís NKP Berkshire #779 in Diamondhead, Mississippi
at the 2005 International Steamup. The beauty of this engine made it
irresistible, and I put my deposit down for a kit on the spot. I have been
looking forward to building it ever since.

This engine has several features that I was particularly interested in
discovering how they worked. Building these locomotives, have been one of the
best learning projects I've ever experienced. The following is my report on the
assembly, and how I went about building this beautiful locomotive.

One of the first surprises I found with this kit is that Aster changed the
format of the assembly manual. Instead of having two manuals for assembly there
is only one; and instead of using the exploded drawings they used photographs
complete with assembly notes all in one. This will be a new experience, as I
have grown used to the old way of building Aster locomotives.

Pilot Truck

In the past Aster has given a sequence for assembly they recommend following,
but I have several times put most of the assembly together, only to get to the
last part, and find they should have had you install this part much earlier.
I've had to disassemble the work just to get this part installed, and then
reassemble everything.

I found this to be true with the very first assembly step which is the pilot wheel. Part #
A3 the pilot truck stretcher, needs to be installed before the # A1 journal box
frame, then install #A1 running the screw driver through the triangular hole in
the pilot truck frame #A2 to tighten the pan head screw. When you are ready to
install the wheels on the pilot truck assembly give the journal box holder #A9
threaded rod, a trial fit before you install the journal box. The holes for the
rod were not lined up on my kit, and I had to file, ream, and re tap to get it
to fit. If you scratch the paint on this I found a black Magic Marker covers it
quite well.

Trailing Truck

This is pretty straight forward, and only needed a little filing on the journal
boxes for a smooth fit. Upon completion of this impressive piece you will notice
what a heavy duty work horse, you are building.

Main Frame

The next step is the building of the main frame. It is advised that you assemble
this on a piece of heavy glass. You will want to take your time with this,
because it is critical to build it perfectly straight. The slightest warp will
cause unbelievable binding problems later, so be sure it sits square on the
glass, without any rocking. Itís amazing to think the full size frames were cast
in one pour, and that usually included the cylinders!

After the main frame is built the suspension system is installed. The equalizer
fulcrum # C25 is a very tight fit into the guide #C26 and C27. I found that it
snapped into place with a little tap from a small mallet. Once you have the
whole suspension assembly in place, oil all the joints, and be sure to add oil
between the triangular pieces and the frame. These pieces slide back and forth,
and will rub against the frame.

Once the wheels and brakes are added you can see what a gem this locomotive is
going to be.

Axle Driven Pump

The next two steps are the assembly of the water pump which is a new sleek
design. This has a hinged joint in the push rod that bends slightly when
running, so be sure to line the hinge vertically to keep the O-ring properly
centered. The step following this is the linkage for the cylinder cocks, or
drains.

Cylinders

The cylinders are the next assembly. Once again Aster has come up with a better
design. The top of the cylinder, which when assembled is the floor of the steam
chest, is now a separate part. This makes lapping much easier, because instead
of lapping the whole cylinder, which can be awkward, and take the true square
off the cylinder top, you now have a flat plate, which is lapped separately,
then installed with a gasket.

A word of caution: the steam ports, and the milled out valleys, are very small,
so the amount of silicon that is applied to the gasket should be very thin, so
as not to block the ports.

The valves for the cylinder cocks are installed before the lapped plate, and the
steam chest. Then the steam chest is installed to the top of the whole cylinder
assembly, with another gasket. Pay attention to the tapered bolt holes, and the
opening for the piston rod in the steam chest. It is not very noticeable in the
manual, but these can be over looked, and if installed incorrectly the top of
the steam chest will not close.

When assembled, the top of the steam chest complete with tapered screws should
be flush, so the roof of the steam chest will seal tight, when screwed into
place. One other point to take note of is part #F8. This is the valve for the
cylinder cocks. As noted in the manual both pieces are mounted with the extended
finger on the right side. This is so the left side, which is folded down into
the groove first, then the right side is folded down, and will cradle into the
recess created by the left side. This way, as the cam, part #E16 & E17 is
turned, it will push down on these two arms, and open the cylinder cocks.

The cross heads and linkage will take a little time to assemble, but following
the book shouldn't be much of a problem. The steam chest cover on my locomotive
needed to have the holes drilled out. The screws would not fit. First I tried to
ream them out, but the material is too hard, even filing didn't work very well
so I used a #44 bit, and drilled the holes out. This worked very well.

Another part of the cylinder assembly which I found to be a challenge is the
linkage arm that extends down from the lubricator just behind the cylinder, and
directly over the cross head guide. Aster supplied a roll pin to connect the
leakage together. I found this to be impossible, and almost broke the tiny arm
trying to get the roll pin in. Instead, I got a dressmakers straight pin, cut
half the pin off, then bent the pin first, then slipped it through the hole.
Cutting off all that wasn't needed of the pin; I bent it around toward the front
only bending the pin against itself. Don't try to bend the pin against the
linkage because it isn't strong enough. The finished product looked much better than the
roll pin.

There are a few more pieces to assemble on the cylinder assembly to complete it.
The next part is the Baker valve gear. This is very straight forward in the
assembly, and a very interesting part to watch work, once it is finished.

The mounting of the cylinders and valve gear are the next step, and should be
done carefully to insure all parts move freely when done. Follow the manual
it covers all the necessary advice needed, including loosening some of the
screws so the parts can be checked for ease of movement when re tightened.

When all this is completed the linkage for all the wheels are installed. This is
very exciting because you now have half the locomotive built.

Valve Setting

The valve setting is slightly different on the Berkshire
from earlier Aster Locomotives. Before, you needed to work with the angle of the
eccentric crank. A piece of card stock, cut to the proper angle, was the best
way to set this. The new way is to measure from the axle centerline to the
center line of the eccentric pin. This is much easier to accurately set the
eccentric crank.

Once all this is done the air test is run. If all works well, you should go
back and tighten all the screws, as well as using the silicon sealant to seal off the
top of the steam chest. Then install the covers on the steam chest and the base
for the smoke box.

The air test will give you a feel for what a great runner this locomotive is
going to be. Once you have run it, sit back and admire your work.

To finish the cylinders several things were missed in the instruction manual.
Sealing the top of the steam chest is the first. The gaskets, that up to now
have been installed dry, should be removed and covered with a fine layer of
silicon to completely seal the steam chest off. The imprint of the top wall of
the steam chest should be impressed on the gasket and I would recommend only
applying silicon to the perimeter. You want to avoid any excess silicon getting
into the slide valve. The next is reinstalling the gear frame part #G16 & G17
to the front of the Baker Valve Gear, before you install the outside covers of
the cylinders.

The Boiler

The firebox is straight forward with one exception. I believe Aster is buying
the ceramic sheets from another vender. In the past I would cut the sheet to fit
the application, then apply silicon to the sheet and install it in place. This
ceramic sheet has a coating on it which prevents anything from adhering to it. I
applied silicon to the part I was lining instead, and then applied the ceramic
sheet to it. For some reason this worked fine, and within an hour the silicon
had dried and the ceramic sheet was firmly attached.

Now for the boiler. Aster has come up with a new design for the sight glass. I
found it takes a bit of fiddling with the brass ends to get them to fit into the
steel mounting bracket. If you keep working with it, it will go together without
filing or re tapping. Installing the O-rings to the sight glass is always a
challenge. I find using the backside of a dentist pick with a close curve toward
the end, (not the sharp side) is helpful in pushing the O-ring into the brass
sealing ring.

The back head is assembled which only needs a few comments. Be sure to install
the whistle with the opening facing down, so any water that accumulates from the
use of the whistle will empty out. The control stem is a very impressive unit
that goes together without any problem. Itís a very sleek design, and
compliments the cab of the locomotive.

Installing the piping uses two different banjo bolts. One type has a large
opening, and is used for the sight glass. The bolts with the smaller openings
are used for everything else. This is a very nice assembly because all of the
piping is preformed, and fits very well.

The burner wicks are cut and placed, and the unit is then put away for later
installation.

Air testing the boiler may be easier to do if you inject the air into the check
valve rather than the drain valve as indicated in the manual. It will depend on
the air fittings you have on hand.

Boiler Casing and Fittings

Putting all the fittings on the boiler casing is like a double edge sword. Itís
exciting to see the locomotive forming as you add the fittings, but you must be
so careful, because your work here is what really shows. One scratch or broken
part, and everyone that looks at it may see it! Keep in mind your best friend
here may be the black permanent magic marker.

I found all the parts fit very well until I started installing the sand pipes to
the sand dome. Aster has revised the way the sand pipes fit, and I found the new
method to be exceptional. I did find, however, when they painted the sand dome,
the paint ran into the holes where the sand pipes fit into the sand dome. These
needed to be drilled out again. I also drilled them a little deeper than they
were originally, just to allow for more working space. If you do this you, will
need a #61 drill bit, and I must warn you to be very careful because breaking a
drill bit inside of a hole that small, can be impossible to remove.

Once the holes were drilled I pre-formed the sand pipes using my fingers to
conform to the curvature of the boiler case. After I had all the pipes roughly
curved, I worked with the boiler case upside down, first fitting the pipe into
the elongated slots, then into the sand dome. The pipes fit without any trouble.
Then using a toothpick I applied a tiny amount of super glue to the joint where
the pipes run into the sand dome, just to insure they stayed in place.

Running Boards

Bending the wire for the pipes that run under the running board was not
difficult. Spend all the time it takes to do it carefully. I used the handle of
an Exacto knife which measured 8 mm to do the bending.

Smoke Box

The smoke box has a few fittings installed. Then you add two layers of ceramic
sheet insulation. The important thing here is to remember to leave space for the
smoke box front to fit tightly up against the insulation. I also found if
you use too much silicon on the inside of the smoke box it will exude out
through some of the holes where the fittings have already been installed. Use
caution around all the holes in the smoke box. Clean off any silicone that
exudes through the holes immediately.

The smoke box door is installed using the roll pins for hinges. Once again I
found these to be absolutely impossible. I did manage to press one in on the top
hinge, but before I could get anywhere with the lower pin it shot out of the
tweezers and was lost. As in the earlier case I used a dress makerís pin with a
head on it, and it worked, and looked perfect. This smoke box is a very
impressive addition, with all the headlights, number boards, and fittings.

The Cab

Assembling the cab always feels like a reward, because now you can see what all
the parts of the locomotive look like. The fittings for the cab go together
without much trouble. The tabs on the wing window frames must be bent out so you
can install the frame to the cab. Then the tabs need to be bent back and the
wing window glued in place. Care must be given to get the right mounting piece
on the right hand rail for the rear of the cab. The little tabs are bent
together to hold the hand rail in place. Once these are installed you want to be
careful about placing the cab down so you don't bend the handrails.

The floor assembly should go together without a problem. One thing that is
not very clear on the instruction manual is where the washer #M24 is
supposed to go. This is installed under the floor with a M2 2.5 screw to
the bottom of the reverser handle, to keep it in place.

Front Coupler Beam

The front coupler beam is a beautifully designed piece. Once assembled the
knuckle coupler works just like the real one. When installing the connecting
wire for the lifting pin in the coupler, the wire must be slightly straightened
so the wire will run through the hole in the lifting pin. Just straighten it
enough to get it through the hole then bend it back to its original shape.

The ladders must be mounted with the threaded hole on the top of the ladder.
This will later screw the ladder to running board.

Front Deck

The last assembly for the locomotive is the front deck. I found the only
difficulty with this was the compressor jacket and holder, parts#02/04 and
#03/05. Looking at the picture in the manual its difficult to see which way is
up or down. If you assemble them so the compressors (one per side) is mounted on
the bottom, and the top is open, you will have it assembled correctly. The deck
step, part #011 is temporarily mounted and will need to be taken off later to
mount the whole front deck assembly to the frame.

Now that you have assembled all the component parts for the locomotive, and are
anxious to see what it looks like assembled, Aster has you put all these parts
to the side and start building the tender. I assume they figured, since youíre
in the building mode, you should stay there and keep building.

The Tender

The tender is started with the assembly of the Buckeye trucks. I found these
fascinating in design. They are built to run on very uneven track and keep a
tight grip with wheels firmly on the track no matter how much the rails rock and
roll. The manual is very straight forward, and easy to read here. A little time
should be taken to pre-bend a ninety degree angle in the wire for the journal
box doors, slip it into the hinge on the door, bend another ninety degree bend,
and cut the wire off on both ends to make it a neat job.

Once all the doors are mounted the next step is to add the wheels to the truck, run a screw through a washer into the axle inside of the journal box
just like the real one. The rest of the assembly is clearly outlined until you
get to the very end. The #P20 x 2 washers are set aside until the trucks are
mounted to the chassis.

When the tender floor is assembled please note there are two different sets of
ladders (two each). One set is angled to one side and the other set is straight.
The angled set is the one that is mounted in the front. The knuckle couple is
assembled the same as was just done for the locomotive.

The draw bar locking release is assembled, and the manual calls for a #M2 black
nut to be placed on the bottom of the handle. This is the wrong nut it should be
a #M2.6 silver nut.

The sump is mounted with spacers placed on top of the floor so the sump sits
half way above the floor level and half way below the floor level. This is a
different design than past models have used. The truck mounting brackets and a
few detail fittings are added to complete the floor assembly.

The tender body is clearly outlined with one detail that may be in question. The
rail that goes around the top of the tender deck is all pre formed. Rail #R4
runs down the left side, and #R6 runs down the right side (this rail has a
ninety degree bend in it). First thread the rail though all the stanchions on
the right side. Then the small bend on #R6 is bent out so it makes the corner
and runs about half way into the rail stanchion on the rear end of the deck. #R5
is a small straight piece that runs across the back and the end slips into the
other half of the same rail stanchion, making it look like the whole rail is one
piece.

The tender water pump is assembled, and mounted next. The only thing to note on
the pump is the #R20 cover has a hole in it, and it is mounted facing the bottom
of the pump. I would recommend applying silicon to the treads of #R19 & R20. Be
sure to check to hear the steel ball rattle when the covers are tightened. If
silicon gets on the steel ball the pump won't work. When mounting the pump be
sure to apply silicon to the bottom of the pump, so the mounting screws are
sealed in. One other place to silicon in is both of the ends of the water tank.
I have completely assembled tenders, taken the locomotive out to fire it up, and
find the tender water tank leaks. Silicon all the joints and corners to make
sure it is water tight. Let the silicone cure overnight before testing. Another
great addition to this tender is the water tank has a drain with a removable
plug. To finish the water tank the two copper water pipes are connected to the
water tank and it's ready to mount to the body.

The flow regulator, and the filler cap are installed on the alcohol tank, and
the rubber hoses are readied for installation. The alcohol tank is another new
improvement Aster has incorporated into this model. The alcohol tank is a lift
out tank, and can be taken out of the tender completely to fill or empty it. In
an email with Hans Huwyler of AsterHobbyUSA, Hans told me the ample space
underneath the alcohol tank is for radio control equipment. Once again the
improvements on this locomotive are outstanding.

After the body is assembled the hoses for water and alcohol are installed, and
the trucks are put in place using the #P20 x2 washers, and M3 nut. Now sit back
and enjoy looking at your new tender. Just its size is impressive.

Locomotive Final Assembly

The final assembly has been carefully thought out by the design engineers. If
you carefully follow the manual you should have no problem finishing your
locomotive.

Here are a couple of suggestions that might save you some time.

The first is the application of the ceramic sheet strips, used to seal off the
space between the boiler, and its casing. On the last Aster locomotive I
assembled (The Duchess of Sutherland) I was able to use silicon and adhere it
right to the boiler. Then using a piece of paper as a funnel I slipped it into
place neat as a pin. This didn't work on the Berkshire, because there are too
many obstacles in the way.

I would recommend using the boiler as a template applying four or five layers of
the ceramic sheet strips glued together with silicone around the boiler (do not
apply silicon to the boiler as the strips should not be glued to the boiler yet).
Start and stop the strips in the same place, so you have a seam that runs
through all the layers. Let the silicon set for a half hour, then carefully
slip them off the front of the boiler opening the seam as needed, but keeping the
round shape.

Next set the boiler into its casing, working from the front, placing the ceramic
circle into the opening, as evenly as possible. You want the front to be straight and even. If you need to trim a little off, do it
carefully. Once itís in place, you can now set the whole boiler on the chassis
and connect the water pipe #D15 to the check valve #I 17. Following the manual
secure the boiler to the chassis, first in the front with Nut #M3 and then Truss
head screw #M3-5. Now that everything is secured, go back to the front of the boiler,
and put a layer of silicon over the ceramic strips, forming
a seal between the casing and the boiler.

There should not be any air flow between the boiler and the casing into the
smoke box. If you follow the instructions it should be clear how the smoke box
is installed. One point to remember, when installing the smoke box be sure
to run the wire on the right side of the boiler into the throttle lever on the
right side of the smoke box. Once the smoke box is installed, you can now
reinstall the blast pipe back in place.

Check the seal around the hole where the blast pipe comes up through the floor.
Also, check the slot in the back of the smoke box, where the super heater
runs out of the smoke box, to insure an air tight seal. Remember a vacuum is
created in the smoke box to create a draft for the heat from the burner to flow
through the boiler tubes then into the smoke box, and out the smoke stack. Any
air leak will seriously affect the performance of your locomotive.

After the smoke box is in place the front deck is installed. The ladder and
coupler assembly went on fine, but the compressor assembly needed to work around
the dummy air hose to fit into place. I found if you tilt the back end up, and
slid the assembly in from the back to the front; it will slide right under the
dummy air hose. Next reinstall the smoke box door. If its too tight a fit, use a
tiny round file making the opening slightly larger.

The running boards and the detail parts attached to them, are installed next.

The floor of the cab should fit in place neatly. If you have any trouble with
the fit, check to make sure the water pipe that is now connected to the check
valve is centered in the slot provided. Finally the cab is installed, and the
hand rails in the back are secured in place.

The linkage rod that runs from the reverser lever, to the linkage under the
running board, is installed and should be tested, to make sure the set screw has
been tightened in the right place. The reverser lever needs to move the Baker
valve gear into its forward, and reverse position.

The pilot wheels, and trailing trucks are the last installation, and need to be
set using the #A 10 washers. Be sure to oil the connecting posts where the
screws are placed.

Now grab a beverage, aim a spot light on the locomotive, and tender, and enjoy
looking at you new locomotive.

Test run

I ran my locomotive the first time, on a cold day so I could see the exhaust. I
did a test run on Aster rollers. I like testing my locomotives on rollers,
because I can monitor everything, and make sure all is well, during the break in
period.

Firing up the locomotive went well; with four burners you really get quite a
fire under there. I used the suction fan until I reached #2 on the pressure
gauge, then opened the blower, and removed the fan. I found the engine needed a
lot of steam from the blower to create enough draft to keep building pressure.
The climb was steady and before long the safety valves had blown.

I set the reverser in full forward position, and opened the throttle just a
little. I reached down to make sure the reverser was full on, and tapped the
throttle and away it went. This locomotive ran smoother, and quieter than my
others. There was a fair amount of exhaust, but it was a cold day, and showed up
much more than I was used to. I found on the test rollers the locomotive ran
almost by itself.

All the controls for running the locomotive are placed so you can reach them
easily. This is a great advantage to prevent burned fingers.

Usually my locomotives run for about fifteen to twenty minutes, but this tender
has a large capacity, and it ran for an hour. I added a little water to the
tender, and a couple of times used the tender water pump just to maintain the
half full mark on the water gauge. Aside from that, all I did was make some
adjustments to the water by pass, and enjoyed watching my locomotive run.

When it came time to close down the locomotive, clean up was much easier with the water drain in the tender and the removable alcohol tank. The blow down
valve on the left side of the cab emptied any excess water out of the boiler.
These are improvements that make an already great locomotive even better.

The NKP Berkshire Kit has been a real pleasure to build and run. Aster has
made many new and wonderful improvements. In addition, the Berkshire
is now the largest locomotive in my collection. The size is impressive, the
attention to detail is unbelievable, and it runs like a top. I am looking
forward to many years of operating this great locomotive.

Southern Steam Trains is grateful for Howard Freedís
generosity, expertise and willingness to write this comprehensive assembly review
of the Asterís NKP Berkshire for positing on our web site.